Orthodontic appliance system

ABSTRACT

A removable orthodontic appliance of discrete plastic sleeves, each being receivable over a corresponding tooth of a patient. Lingual clips are fastened to the corresponding tooth and which are engageable with corresponding structure of the sleeves for removably retaining each of said plastic sleeves to the corresponding tooth of the patient. Buccal brackets are fixably carried on a side of each of the sleeves positionally corresponding to a buccal surface of the corresponding tooth to which each of the sleeves is receivable. An arch wire is ligated to each of the buccal brackets to extend therebetween. The system can be conveniently removed for cleaning and adjustment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation Application of U.S. Ser. No. 12/778,522 filed May12, 2010, which claims priority under 35 U.S.C. §119 of a provisionalapplication Ser. No. 61/270,247 filed Jul. 6, 2009, all of which arehereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

The invention relates to an orthodontic appliance system, and moreparticularly, to an orthodontic appliance system which allows temporaryremoval of the active orthodontic components from the teeth of a patientundergoing orthodontic realignment, for teeth brushing, eating, etc.,and facilitated reinstallation by the patient without the aid of adentist.

For well over a century, orthodontists have been engaged in the processof repositioning teeth from a bad relationship, or “malocclusion,” intoa healthier and more esthetic arrangement. In order to move teeth, threeelements are generally required: 1) force, 2) time and 3) space. Themouth responds to a sustained force placed on a tooth by rearranging, or“remodeling,” the jawbone around the tooth. This remodeling createsspace around the tooth allowing the tooth to move in the direction ofthe force. Not only does the tooth need space within the jawbone, but itis also imperative to have or create spacing between the teeth in orderfor movement to occur.

Over the years, orthodontists have invented devices, generally referredto as an “appliance,” that permit clinicians to deliver sustained forcesto the teeth. Braces, or “orthodontic brackets,” are the classicappliances that most, if not all, orthodontists use. Braces consist ofsmall brackets that are glued, or “bonded,” to the teeth, and a wire isthen inserted into the brackets and held into place with a ligature orclip. The brackets themselves do not deliver forces to the teeth. Theforce is applied when the wire is deflected and inserted into the sloton the bracket and held in by the ligature. The wire has a “memory,”i.e., a characteristic by which the wire tends to return to its originalshape, and in doing so, exerts a force on the bracket that is in turntransmitted to the tooth. Through the application of various types,shapes and sizes of wires, the teeth eventually align themselves into amore ideal occlusion. The technical term used among orthodontists todescribe braces is “comprehensive fixed appliance.”

Because of the obvious drawbacks of having foreign objects glued to apatient's teeth, appliances have been heretofore suggested that can beinserted and removed by the patient. A myriad of removable applianceshave been developed over the years, but the vast majority of them arenot “comprehensive” in nature. In other words, the removable appliancesaddress specific movements or malocclusions, and are only used for acertain limited period of time. Treatment with removable appliances isoften used in conjunction with braces or other appliances.

However, some companies offer clear aligners. Two notably are the ESSIXand INVISALIGN systems, and are presently being used comprehensively asan alternative to braces. Both the ESSIX and INVISALIGN appliancesutilize clear plastic “aligners,” or sheets of plastic, custom molded toan individual's teeth, to induce orthodontic movement.

INVISALIGN uses a technology called stereolithography (computer aided 3Dprototyping) to fabricate a series of aligners from a digitizedrepresentation of the patient's mouth that has been scanned from adental impression. Each aligner creates small, incremental movements, byplacing pressure on the teeth in specific locations as determined bycomputer-generated models. As the series of aligners are worn, graduallythe teeth are forced into a more desirable position.

The ESSIX appliance on the other hand, uses only one clear aligner thatis manipulated by the clinician to apply specific forces to the teeth.To apply force with the ESSIX system, the orthodontist can eithermanipulate the plastic or add volume to the teeth.

All of the previously mentioned orthodontic appliances have bothpositive and negative attributes associated with them. For example, mostpatients dislike not being able to remove their braces to eat and brushtheir teeth. The INVISALIGN system moves teeth much more slowly thanbraces, and is limited in its scope and potential. The ESSIX devicerequires more training by the orthodontist, and is even more limited inits potential applications.

It is therefore an object of the invention to provide a removableorthodontic appliance system which overcomes the drawbacks of the priorart, embodied in a form which is versatilely adapted to individualpatient needs, and which is easy to remove and replace by the patient,when desired.

BRIEF SUMMARY OF THE INVENTION

Broadly stated, the concept behind the device according to the inventionis the creation of a type of “removable braces,” in which the bracketsor other wire holder such as tubes and the wires as well are deliveringthe forces to the teeth without having to be glued or otherwisesemi-permanently fixed to the teeth. Instead of being cemented to theteeth, the for example brackets and wires are attached to a clearaligner. The clear aligner is then sectioned along each individual toothto create discrete plastic sleeves, each which fits over a respectivetooth. The brackets are subsequently attached to the wire, making onecontinuous, interconnected appliance. In order to retain the plasticsleeve on a corresponding one of the teeth, a clip (for examplecomprised of metal or other suitable material) is glued for example tothe backside of each tooth, not visible from the front. The clip allowsthe clear plastic sleeve to adhere firmly to the tooth by engagementthereof with the lingual surface-mounted clip. There is retention secureenough to maintain the plastic sleeve on the tooth, thereby deliveringthe forces from the braces to the teeth, but not too much force that thepatient is unable to remove the appliance with his/her fingers.

The invention will find utility in treating and correcting mild tomoderate malocclusions of both the maxilla and mandible, addressing theneeds of retreating patients who have previously received orthodontictreatment and have experienced relapse and/or can be used as a retainerto stabilize the teeth.

Fabrication and installation of the orthodontic appliance in accordancewith an embodiment of the invention will be described in detail, withreference to drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the orthodontic appliance installed on the teeth of apatient and a custom aligner which serves as an insertion and removaltool;

FIG. 2 shows attachment of an arch wire to the buccal brackets of theorthodontic appliance in accordance with the invention;

FIG. 3 shows the individual sleeves of the orthodontic applianceaccording to the invention;

FIG. 4 is a cross-sectional view of a tooth to which a sleeve isinstalled and held thereto by a lingual clip; and

FIG. 5 is a view of the installed orthodontic appliance showing thelingual surfaces of the teeth in detail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The orthodontic appliance system according to an embodiment of theinvention requires initial preparation and fitted installation for eachpatient on an individual basis. The method of fitting a patient with thesystem is described in the following.

To begin the process, a polyvinyl siloxane (PVS) impression of thedental arch to be treated is taken. It is also possible to obtain amodel of a patient's mouth via an intraoral scanner. The file is thentransmitted to a 3D or CAD CAM printer and a replica is created. Theimpression is subsequently poured in high-strength orthodontic stone,and separated from the impression once the stone is set. The FA point onthe buccal surface of the teeth where the ideal bracket location will beis marked on the casting, for example, using a thin pencil to lightlymark surface. Lingual clips can be removably attached to the back(lingual) surfaces of the cast teeth using a temporary adhesive. Anexample of a suitable adhesive is THERMACURE (Reliance Orthodontics), asis used in the indirect bracketing technique, or any type of temporaryadhesive that will keep the lingual clip attached during the plasticthermoforming process, but will allow for the clip to release from thedental cast once embedded in the plastic, as will be described below.

The lingual clips advantageously have a mesh base similar to aconventional bracket, and a square projection that permits the plastic,when heated and pliable, to form over it. Once the plastic has cooledand is firm, the projection acts as a hook that the plastic clips onto,serving as a type of snap-fit engagement. The plastic is rigid, but hassome flexibility, which allows the plastic sleeve to deform slightly asthe sleeve is pushed in a direction of the gumline, over the lingualclip, and then to snap onto or around the sleeve once it has beencompletely seated. The inherent rigidity of the plastic then keeps thesleeve tightly adapted to the lingual clip until the patient or doctorgrabs the sleeve and lifts it up and over the clip to remove the sleeve.

A sheet of plastic material of suitable thickness is thermoformed overthe dental cast with the lingual clips in place. A suitable material is,for example, a 1.0 mm thick C+, A+ or ACE ESSIX plastic sheet. There arealso several other different types and brands of plastic available forthe dental market. Each plastic was designed and created for a differentpurpose, and they possess unique properties which may be foundparticularly useful depending on the individual application. Theinvention, however, is not contemplated as being limited to these knownplastics. As new plastics are developed with improved characteristics,these can be adapted to the inventive orthodontic appliance withoutdeparture form the invention.

While the thermoformed plastic is still warm, an instrument is used totightly adapt and conform the plastic around the lingual clips, ensuringan accurate fit. It is noted that both types of thermoforming machinescurrently in use, i.e., vacuum or pressure, can be used to fabricate theclear aligner. As with INVISALIGN, digitization and stereolithographycan alternatively be optionally be used to fabricate the clear aligner.

Once the plastic has cooled, the gross excess is trimmed away fromaround the dental cast. Using marks (e.g. pencil) previously placed onthe cast, a bracket 5 (see e.g. FIGS. 1 and 2) is attached to eachportion of the clear aligner corresponding positionally to each tooth.Advantageously, the base of an orthodontic bracket 5 is heated until itjust starts to glow, and it is then pushed into the plastic at the ideallocation indicated by the marking viewed through the plastic. As theplastic melts, it flows into the micromesh of the bracket, andmechanically locks the bracket 5 into place by captive engagement. Thebracket 5 is now tightly adapted to the buccal surface of the tooth asif it had been bonded to the tooth directly, as with traditional braces.The same process is repeated again for appliances that use wires on boththe buccal and lingual sides.

An alternate method to the above, is to bond the brackets to the clearaligner using suitable glue, for example, an epoxy-based adhesive. Usinga similar technique as with bonding to real teeth, the bracket isroughened, primed and bonded to the plastic in the ideal location. It isnoted, however, that in using this alternative approach, since thebracket is not at least partially embedded in the plastic, the thicknessof the plastic causes the bracket to protrude farther forward from thetooth. It is also feasible to create the entire appliance in plastic viathe stereolithography technique. The sleeve, retention and “bracket”portion can all be in plastic fabricated as one unit. A small metalinsert can then be glued into the plastic “bracket” portion.

Once these procedures are completed, a second piece of plastic isthermoformed over the cast, with the aligners clips and brackets inplace (no wire yet being present). This forms a second custom aligner 7,which is advantageously relatively thick but flexible, and which willserve as an insertion and removal tool for the patient, as will beexplained. The second tray-shaped aligner 7 is then set aside until theappliance is ready to be inserted.

With the brackets attached to the clear aligner, sections of the clearaligner that correspond to the individual teeth are cut out, formingdiscrete sleeves 3 (see e.g. FIG. 3), each being receivable on acorresponding tooth 2. This can be done, for example, with a dentalhandpiece, scalpel, scissors or the like. Advantageously, at least about1-2 mm of excess plastic is maintained beyond the gingival margins (seeFIG. 4).

Each sleeve 3 is removed from the cast to ensure that the cuts aresufficient, and that each tooth 2 has its own corresponding individualplastic sleeve 3. The lingual clips (shown attached to the patientsteeth in a subsequently described manner in FIG. 4) embedded inside theplastic will likely be detached from the cast during this process. Witheach plastic sleeve 3 off of the cast, the metal pad of the lingual clip1 is sandblasted to remove any of the temporary adhesive used during thethermoforming process.

Now, work on the patient can be commenced. The lingual clips 1 arebonded to the lingual surface of the patient's teeth 2. Conveniently,using the same bonding technique as with braces, the tooth surface isetched and primed. Orthodontic bracket cement is applied to the metalpad of the clip 1 positioned inside the plastic sleeve 3 one tooth at atime. The sleeve 3 is placed onto the tooth 2 ensuring that the sleeve 3is seated completely onto the tooth 2. Using finger pressure, theplastic sleeve 3 is pinched to ensure that the metal pad of the clip 1is tightly adhered to the lingual surface of the tooth 2. Using a dentalcuring light, the orthodontic cement is light cured according to thecement manufacturer's recommendations. This process is continued foreach sleeve 3 until all of the lingual clips 1 have been bonded to theteeth. The sleeves 3 can then be removed, leaving the lingual clips 1attached to the teeth 2.

As depicted in FIG. 2, the sleeves 3 are then reinstalled to the stoneimpression cast. An orthodontic wire 4 (usually made of nickel-titanium)is sized and cut, and ligated into the brackets 5. An appropriate ballattachment 6 is advantageously attached to the excess wire 4 at the endof the brackets 5 on either side. This ball attachment 6, while notessential to the invention, serves as an advantageous feature of theinvention, and which is designed to keep the plastic sleeves 3 fromsliding off the ends of the wire 4 when removed from the impression castor the patent's teeth. This ball attachment 6 acts as a cap to the wire4, and has one hollow end 6 a with a diameter just larger than thecorresponding arch wire 4. The other end 6 b of the attachment 6 forms asmall round ball shape that is smooth and comfortable to the patient.The end of the arch wire 4 is inserted into the hollow end 6 a and thenarrow portion of the attachment 6 is crimped or pinched around the archwire 4 to keep it in place.

The second, flexible insertion tray 7 is now placed over the cast andused to pick up the sleeves 3 that are now attached to the wire 4. Theplastic sleeves 3 have a tendency to spin around the wire 4 duringremoval and insertion, and this second plastic tray fits around thesleeves 3 and brackets 5 affording more efficient insertion and removalof the new appliance, by retaining general alignment of the discretesleeves 3. The insertion tray 7 is then fitted over the teeth 2 insidethe patient's mouth, using firm pressure to seat the plastic sleeves 3onto the teeth. Once at least partially seated, the outer insertion tray7 is peeled off of the plastic sleeves 3, and using fingers, the sleeves3 are pushed completely onto each tooth 2 until a click is felt orheard, indicating snap fit engagement of each sleeve 3 to acorresponding one of the lingual clips 1.

The patient wears the appliance as instructed by the orthodontist anduses the outer tray 7 to remove the appliance when eating and brushing.The patient returns for periodic appointments. As the teeth align, theorthodontist advances and progresses the treatment in the same manner aswould be done with traditional braces.

Once treatment is completed, the appliance can be worn as a retainer tostabilize treatment as directed by the orthodontist.

It is to be understood that the above disclosure represents one exampleof the mode by which the invention can be practiced. Other, alternativemeans for accomplishing the goals disclosed herein can be utilizedwithin the contemplated scope invention, without departure from thespirit of the invention.

For example, the precise nature of the lingual clip 1 need not belimited to that of the above described example. The lingual clip 1 maybe evolved into two separate parts; one male and one female. The femaleattachment would, for example, be bonded to the tooth, to be smaller,and less prominent. It could conceivably house a locking mechanismadapted to receive the male attachment embedded in the plastic sleeve.

In addition to the lingual clip 1, a small mound of dental compositecould be added to the facial surface of the teeth below the bracket foradded retention.

Additionally, while the invention as disclosed above utilizes stainlesssteel brackets 5 attached to the plastic sleeves 3, alternatively, clearplastic or ceramic brackets may be utilized for a more esthetic optionfor the patient.

In accordance with a further alternative example, a lingual bracket maybe incorporated into the sleeve on the lingual side of the appliance. Alingual archwire can then be used congruently with the buccal archwireto deliver better forces to the teeth thereby achieving faster treatmenttimes.

It is noted that the appliance according to an embodiment of theinvention will be applicable as a long-term retention solution. In suchuse, the lingual clips will remain on the lower anterior teeth and theappliance will be worn at night. If the patient forgets to wear theappliance or experiences relapse, the wire will deflect slightly toaccommodate for the misalignment of the teeth and bring them back intoalignment. This is a departure from conventional fixed retainers whichhave to be remade if the teeth shift. The invention according to thisembodiment also serves as an advancement over conventional fixedretainers, insofar as being able to remove the retainer will improvebrushing and oral hygiene.

Finally, unlike traditional braces, the orthodontist can remove theappliance during the periodic appointments to change wires and makeadjustments. An additional model or cast, with lingual clips, can befabricated and kept by the orthodontist for the adjustment appointments.

What is claimed is:
 1. A removable orthodontic appliance system,comprising: discrete plastic sleeves each receivable over asubstantially all of the visible surface of corresponding tooth of apatient; lingual clips each being fastened to the corresponding tooth ofthe patient, said lingual clips being engageable with said discreteplastic sleeves for removably retaining each of said plastic sleeves tothe corresponding tooth of the patient; buccal wire holders fixablycarried on at least one side of each of said sleeves positionallycorresponding to a buccal surface of the corresponding tooth to whicheach of the sleeves is receivable; and an arch wire fastenable to saidbuccal wire holders and extending therebetween, said appliance systembeing patient removable with fingers for cleaning or adjustment.
 2. Anappliance system according to claim 1, further comprising: an insertiontray dimensioned for conformable reception over the plastic sleeves andarch wire.
 3. The appliance of claim 1 wherein a bracket is carried onthe at least one side of said sleeves on the buccal side.
 4. Theappliance of claim 1 wherein brackets are carried on both the buccal andlingual side of said sleeves.
 5. The appliance of claim 1 wherein thearch wire is a memory wire.
 6. The appliance of claim 1 wherein the wireholders are buccal brackets.
 7. In an orthodontic appliance for movingteeth, the improvement comprising individual discrete plastic sleeves,each fitting over substantially all of the visible surface of a tooth,and each adjusted to receive an arch wire to make one continuous movableand removable appliance.
 8. An orthodontic appliance of claim 1 furthercomprising an insertion tray for comfortable reception over the discreteplastic sleeves and arch wires.
 9. A method of moving teeth with adental appliance, comprising forming individual discrete plastic sleevessubstantially all of the visible surface for each tooth to be moved;adapting said sleeves to receive a memory set arch wire; and attachingthe memory set arch wire to said sleeves to make a continuous butremovable appliance.
 10. The method of claim 9 wherein memory set archwires are fastened to both the buccal and lingual sides of said sleeves.